Blood levels of HDL, the famously "good" kind of cholesterol, may not make a big difference to heart health after all -- particularly for Black people, a large new study suggests. The study, of nearly 24,000 U.S. adults, found that low HDL levels were tied to a somewhat higher risk of heart attack among White people. That was not the case for Black adults, however. Meanwhile, high HDL levels -- traditionally lauded as heart-healthy -- made no difference in heart risks for Black or White adults. Experts said the findings call for a reevaluation of how HDL is used to...